The present invention relates to the field of identification or ID cards, and more particularly to cards bearing facial images.
For many years ID cards bearing facial images have been the most popular means of restricting access to industrial and military establishments, hospitals, liquor stores and so forth. Photographs have also been used to identify the bearer in the issuance of drivers licenses, passports and other types of ID cards. In the age of terrorism, the prevention of counterfeiting of plastic ID cards, particularly those functioning as passports or national ID cards and sensitive area access badges, is becoming more and more important.
The use of facial images is highly practical since, at least theoretically, the bearer's actual facial image is readily matched with the image on his card, often worn as a badge by, for example, a guard at the entrance of a large company. The use of facial images, in theory, employs the human eyes and brain of the guard, which constitutes a widely available computer, and a facial image carries much information to authenticate the bearer of the card.
It is believed that conventional fairly costly photos for use on ID cards will in many cases be replaced by high speed electronic printers such as ink jet printers. At the issuing station, an electronic camera will scan the face of the bearer, and an array of pixels, having intensity level and color information defining the face of the bearer will be recorded within a small computer and will be thereafter printed on the ID card along with the usual printing indicating the name of the bearer and issuing agency, etc.; see U.S. Pat. No. 4,687,526 issued to Wilfert, and "PC Graphics", Electronics magazine, April 1989.
However, ID cards such as drivers licenses, company badges, liquor store IDs etc. are easy to counterfeit by the substitution of the facial image of an unauthorized bearer, photographed in conjunction with a background field of appropriate printed indicia. Inexpensive laminators and plastic envelopes are widely available to anyone wishing to make counterfeit cards in this manner. As indicated in the Electronics magazine article, relatively inexpensive printers for making photo quality images under the control of PC software should be available in the next couple of years, so that counterfeiting with such apparatus will readily occur.
Other numerous techniques for thwarting counterfeiting are disclosed in the art. Digital data recorded upon the card having a scrambled key embedded therein is unscrambled by an algorithm, and the unscrambled key is compared with a password inputted by the bearer; see Yamamoto U.S. Pat. Nos. 3,665,162 and 4,739,377 issued to Allen. A counterfeiter can however sequentially input large sequences of numbers into the card reader using a PC to find the appropriate matching password for use with stolen cards. Also, the algorithms themselves can be discovered by examination of the data on a plurality of stolen cards. The use of various non-biometric encoding devices embedded within cards to be matched with a personal password keyed in to a verifier by the bearer of the card has also been suggested. See U.S. Pat. No. 4,682,794 issued to Margolis.
Another problem with these techniques is that biometrics is not employed, that is, the infinitely variable physical features of a bona fide bearer are not used for bearer verification by the most widely available computer, namely the human brain and eyeball. Thus numerous patents disclose techniques utilizing biometrics in an attempt to enhance security relative to the practical and thus ubiquitous photo ID card, whereby unfortunately, the photo of an unauthorized bearer may be easily employed on a counterfeit card.
Distortion of an image of a characteristic of the bearer by optical means is suggested in a number of patents. The face of a bearer is distorted and recorded on a card and is thereafter read by a complementary optical device to display the undistorted image. U.S. Pat. Nos. 4,765,656 to Becker, and 3,922,074 to Ikegami teach the use of lenticular lenses for this purpose. Scrambling of an image by fiber optic bundles is known in the art, while U.S. Pat. No. 4,532,508 to Ruel teaches distortion of a holographically printed image of the bearer on the card. However, these approaches have not been widely utilized in the market due to their increased inconvenience, complexity, cost or unreliability.
U.S. Pat. Nos. 3,914,877 to Hines and 4,776,013 to Kafri teach recording a jumbled image for security purposes. Since masking is utilized for this purpose, the conventional gray scale intensity and/or color information is not retained during processing to be utilized to recreate a facial image having sufficient fidelity suitable for bearer verification, and thus this approach is not relevant to the purposes and modes of operation of the present invention.